Tazkirul Quran تفسیر: As-Saffat آیه 10

‘The lowest heaven’ (as-sama’ ad-dunya) perhaps refers to that part of space which is nearer to man and which can be seen with the naked eye. The creatures such as the jinn attempt to fathom information about the unknown. But in the lowest heaven itself the arrangement is such that any such brazen endeavour is disrupted by occurrences like the shower of meteors.